Method of treating water jackets for engine cylinders



April 2, 1946. w GRAVES 2,397,481

METHOD OF TREATING WATER JACKETS FOR ENGINE CYLINDERS Filed July 18, 1944 'lllll' tion only, or at least to a less extent in such Patented Apr. 2, 1946 2,397,481

UNITED STATES PATENT OFFICE METHOD OF TREATING'WATER JACKETS FOR ENGINE CYLINDERS William H. Graves, Huntington Woods, Mich., as-

signor to Packard Motor Car Company, Detroit, Mich., a corporation of Michigan Application July 18, 1944, Serial No. 545,516 s 1 Claim. (01. 29-1564) This invention relates to a method oi treating apparatus for use in practicing the method of the the coolant jackets of internal combustion eninstant invention;

gines,'hereinafter referred to as water jackets, to Figure 2 is a transverse sectional view taken increase their resistance to cracking during opersubstantially on the line 2-2 of Figur 1;

ation of the engine. 5 Figure 3 is a plan view of the upper end of a For reasons of efficiency and economy it is the cylinder;

practice in the building of certain types of en- Figure 4 is a bottom plan of one element of the gines, especially marine engines, to form the apparatus showing the means for closing the water jackets of fairly thin sheet metal, which water outlets of the cylinder illustrated in Figis bent into cylindrical shape, Welded lengthwise, l ure 3; and

and welded at its upper and lower ends to the Figure 5 is a vertical sectional view taken subengine cylinder. While these jacket are substantially on the line 5-5 01. Figure l.

jected in use only to the relative low pressures ex- In order to facilitat the description of the isting in the water chambers thusformed, they invention and to promote an understanding of its are subjected to repeated and wide variations principles, the invention is illustrated by a speof temperature and induced stresses which not cific and preferred embodiment thereof. It will uncommonly result in fatigue and ultimate nevertheless be appreciated that various alteracracking of the jackets. It has been found that tions and further modifications of the illustrated these defects can be overcome by subjecting the Structure are contemplated such as fall within jacket to a preliminary treatment whereby the the purview of the invention and especially Withmetal of the jacket is distended. One efiect of in the scope of the cl ppended hereto.

this treatment is to produce in the jacket com- Turning now 110 e drawing in which is i luspressive rather than tensile stresses, with the retrated an apparatus to faci tate pe rmance of sult that tensile strain are materially lessened thermethod of the present invention, an en and failure due to cracking is substantially elimcy r indicated at having 21 depending inated, lar ll adapted to be received within a crankcase It is therefore an object of the instant inven- Opening and a flange eby t e cylinder tion to provide a method of treating the jackets may be bolted in p t on the crankcase, is of internal combustion engine which includes seated on a sultable p r A water jacket the steps of assembling the jacket to the cylin formed of Sheet metal l t i ge eral cylinder' and applying to the water chamber thus dflcal Shape d Welded at its ends as indicated formed a fluid pressure substantially in excess at and to cylinder flanges, Surrounde a d s of the pressure existing in the chamber during Spaced m the external Wall of the cylmde! use of the engine, whereby the jacket is disto provlde therebetween, as Shown at f tended or stretched, and thereafter relieving the Flgllre an annular water c1}amber- ThIS irtziisdzz ssistrt i Preferably the jacket is confined during theap- W 6 5 i 81 g 5 Own plication of this excessive pressure so as to limit m Flgure formed m the plate 23 which closes i 40 earnerdarted. his; 23s of the Jacket may be hmlted In one lateral dlrec munication With the interior of the cylinder and direction. so as to assure adequate clearance for 823 s gii g ig fiig g zi 5 3 2 ig gi g fgz gf e assembheg 9 adlaceqt Cyhnders m P in position. The cylinder i provided with spark aligned multi-cyhnder engine. The excessive plug bosses 28 the water jacket surrounding and D P y be applied through-0119 of the Openbeing welded to these bosses. Secured to the ings in the Jacket provided for the circulation of jacket by Welding is a water i j t nipple 9 water when in use, the other openings being through which water is caused to fl w in the closed; a suitable fluid for applyl g the Pressure water chamber during the operation of the en- 15 water. gine, being discharged through the water outlet Further objects and features of the invention openings 22 t t cylinder he from henc will beapparent from the following description ii; i discharged, taken in connection with the accompanying I The structure thus far described is convendrawing in which tional and the details thereof form no part of the Figure 1 represents an elevation of one form of instant invention. It is intended merely to rep- 2 resent a cylinder structure which employs a water jacket of sheet metal which may be treated in accordance with th method hereinafter described.

In the application of this method, fluid under pressure, for example water, may be introduced into the water chamber through the water inlet nipple 29' by means of'a coupling 32 on the delivery end of a hose 33, the coupling being suitably designed to engage securely but releasably with the inlet nipple 29.

Mounted above the jacketed cylinder is a device for closing the water outlet openings 22 in the top cylinder plate 23. This device may include an air operated cylinder 35 having therein a piston 36 secured to plunger 31 which carries at its lower end a plate 40 having bosses 4| formed in the axis defined by the row of cylinders, it being obvious that undue expansion in this direction would make the assembly of the cylinders diflicult or impossible to accomplish.

For this purpose, I may employ the apparatus shown in Figures 1 and 2 which comprises essentially a clamping member having arms 50 and 5| embracing the cylinder'over a substantial portion of the depth of the latter. These arms are pivoted together as indicated at 54 and are operated by links 55 pivoted to the respective arms at 56 and to a plunger 58 at 59. The plunger 58 is carried by a piston 62 and may be moved toward the engine cylinder by air or other fluid unon the lower side thereof in number corresp'on'd-' lower facesof these bosses may be provided with a gasket material or otherwise treated to insure a tight fit when pressed against the upper surface of the plate 23 of the cylinder.

Each boss 4| is apertured to communicate with the water outlet with which it engages, and these apertures are connected by ducts 43 formed in the plate 40. A bleed valve 46 communicates with the ducts 43 and with the openings in the bosses 4|, so that when a fluid such as' water is forced into the water jacket through the inlet nipple 29, air may be discharged from the water jacket by opening the valve 43 until the water completely fills the jacket. A check valve lfivmay be provided for attachment of a pressure gauge.

It will be appreciated from the foregoing that when the Water outlets 22 are closed by the apparatus disposed immediately above the cylinder, and water or other fluid is delivered under pressure to the water chamber through the inlet nipple 29, the water jacket 15 is distended or stretched preferably resulting in a permanent set. A suitable pressure for this purpose is one of the order of 700 or 800 pounds per square inch, but

will obviously vary depending upon the char- I acter, and thickness of the water jacket being treated. In any event, the pressure is many times the pressures normally existing in the water chamber during use of the engine. Following the application of adequate pressure and accompanying distention of the jacket, the pressure is released and the cylinder is ready for mounting in the engine crankcase.

It has been found desirable, as hereinbefore indicated, to limit the expansion of the water jacket.

There are several reasons for this, one being the" eral direction which, when the cylinder is as? sembled in an aligned multi-cylinder engine, lies der pressure in the cylinder 6|, the links 55 af- .fording a toggle action so that adequate resistance to outward displacement of the arms is afforded once they. are moved into engagement with the cylinder jacket.

Preferably the inner surfaces of the arms 50 and 5! deflne a shape which is slightly oval rather than circular in transverse section. In this wayv the expansion of the jacket in one lateral direction will be restricted to a dimension less than in the direction at right angles thereto, so as to insure that adjacent cylinders in close juxtaposition.

It will be appreciated that the apparatus described herein for carrying out the method is intended only for the purpose of illustration and that it may be varied widely. In fact, the essential features of the invention may bepracticed without resort to any apparatus other than 7 some means for applying a high pressure to the In a method of treating water jackets for aligned cylinders of multi-cylinder internal combustion engines to eliminate failure caused by stresses during use, the steps which comprise assembling the water jackets to the cylinders andapplying to the water chambers thus provided -a fluid pressure substantially in excess of the pressur for which the jackets are designed when-in use, so as to expand the jackets to an extent sulficient to effect a permanent set, simultaneously confining the jackets. to limit the expansion thereof in a lateral directionv corresponding to the longitudinal axis defined by the several cylinders when assembled in the engine, so that the expansion in such direction is substantially less than in a direction normal thereto, and so that the outside diameter, measured in. such direce tion, of each jacket wall when expanded is not greater than the distance between the cylinder axes of adjacent assembled cylinders, and thereafter releasing the excessive fluid pressure.

WILLIAM H. GRAVES may be mounted 

